Thermal time switch



March 24, 1936. J. LANDAU THERMAL TIME SWITCH Filed Sept. 22, 1930 Aer/M710 & 6/

m w M w W 2 7 A 5 A FIG. 5

Wu A MP. N A ]L. b O C A v A ff 007a 'Myinvention relates tci improvements in time switches, and has among its objects the production of such devices which shall be extremely Pi simple in operation and construction, oi oomparatively few parts, strong and durable, economical, reliable, and eflicient and satisfactory for use wherever io'und applicable.

It is apparent that there are many instances where it would be highly desirable to have a switch which would turn ofl the electrical device which it controls, after a substantially predetermined period, this' breaking of the electrical cir-. cuit to be. accomplished such placewhere a switch of this nature would dwould1bethe switch that controlsthe lights in a child's bed room, another place might be the switchthat controls closet lights, and there known manner.

innumerable other places where'lights, mo-

prior to the automatic shut oil, andat the end 01' the period, will automatically shut oil and stay shut oil until again turned on manually.

One of the objects 01' my invention is-to provide' a thermostatic element that will be thrown heat-actuated thermostat. into the circuit with the. turning on of the switch, and which will become heated up gradually until it will expand sumciently to actuate the switch release, whereupon the circuit and will remain so until the switc is again manually reset to circuit closing position.

Many other objects and advaiages oi the conv ction' herein shown and described, will be obvious to those skilled in the art to whichthislinn' appertains, from the disclosures herein To this end, my invention-consists in the novel construction, tion or parts herein 'the uses mentioned, and more particularly pointedoutintheclaim. 2. I In'the drawing, wherein I have illustrabd prewtact myinvention, andwhere- Patented Mar.-

.zmm rmxsr, 'rms wrron Jacob Landau, rem, city, 1w. r. Application September 2:, mo, Serial No; new

1 cum. toe-12's) in-like teferencecharac proved switch;

certain of the parts in automatically. One

used 7 cuit, the coil II will rec upwards, unless turned 01'! manually ment 'l'is correspon entirely broken element will 'be held 'ement and co'mbinaown anddescribed, and

itself from the switch ll indicata the UNITED [STATE-IS PATENT OFFICE ters indicate like or corresponding parts throughout the views, lisaplanviewoione Iormotmyim- Figure 2 isa'plan view of another form, with 5 section; and

Figure 3 is a side elevation showing one manner I 01- application or the device.,'

Referring more particularly to the drawing, the switch shown in'Fig, 1 shows thepair of lead contacts I and 2, the form shown being a simple single-throw switch, placed in series with any suitable electrical device that is desired to be controlled theretrom,'the same. not being shown as it forms no part of the invention.

The conductors 8 and 4 lead to the contacts land 2, in the wellv A switch element 5 may be arranged to control tors,- or other electrical devices are desired to be the P sag of l c i al u r through 15116 shutv foil automatically after a substantially .predeterminedtime It is well-known that thermostatically con-\- trolled electrical control devices have been used as "flashers", etc., but in such instances, the current when shut oil, will automatically be turned on again after an interval, and the make and break of the circuit will be repeated continuously until the main switch for the circuit is turned 01!. In the present invention, the current isturned'on manually and stays onfor a substantially prede- ,termined period of time, preierably irom a iew switch, to make or break the circuit, said switch element being movably mounted, as for example by pivotally mounting the same upon the pin 8, although it is to be understood that any desired movable mounting of the switch element may be A heat-expansible element Ifaddacent a heating coil II, may be interposed in the circuit so that when the switch element is moved to its position to bridge across the contacts or to make the cireive current item thecir '3 cuit'and. will become As the element ill becomesdifireasing y h d. the

lyheatedanditexpands or elongates, the expansion being dependent upon the characteristics of the particular metal used for the purpom and acting automatically as a.

The element 1 may'- be operably connected to a latch element 8 which is engageable with the switch element, somewhat in the manner shown, so that when [the 40 switch is moved to circuit closing position to turn on ther light or other electricaldevice, the switch in said position by the engagement with the latch 8,

After the thermostatic element l been is heated for a substantially predetermined time, dependent upon vthe particular material used in its construction, it'will have been actuated through asumcient distance to enable the latch to release 1 element. Aspring I or so other suitable means may be provided to throw the'switchelement to its normal open circuit position after its release from the latch.

' wiringiromthecontactlto' the switch element, the same about the u thermostatic element I to heat the latter, and II indicates a switch contact, leading to the other contact 2. From the foregoing description, it will continue to do so until such time as the latter will have been heated sufllciently to elongate the same to release the latch from the switch element, whereupon the switch element will be thrown back to its normal open circuit position.

For various reasons, it y be desirable to provide means Ior turning the current sooner than it would be automatically turned 01!, and for this reasoni have provided means operable independently or the thermostatically controlled means,- to accomplish this desired end. In the form shown, a lever I2 is petitioned to c'o-operate with the latch 8, saidlever being movable to engage with and actuate the latch element to release the switch element. A spring I! may be arranged to connect with the lever l2 to retract the latter to its normal position after movement thereof.

In the modification shownin Figs. 2 and 3, the device is primarily intended for the control of lights and is therefore more compactly constructed, so that the same may be built as a socket or outlet attachment and into which the electric light may be secured in the usual manner.

One oi the contacts leading to the switch indicatedat II, the same being inseries with a coil wound about or otherwise operably connected with a heat expansible or thermostatic element i5 somewhat similar to the element I previously described, whichin thisdiistance maybe more or less arcuate n desired. A hook-or'latch,"

- may be provided at the end of the element I5,

- or it so desired, this latch may be made separately, and preferably connected to and from the element".

A switch element 'i'! is movably mounted so as to make or break the circuit of electricity through the device, said element being pivoted at 18 in the form shown, and having a spring or other suitable device It for retracting'said switch element to normal position after release thereof.

The switch contact 20 engages with said switch element in the closed circuit position, and a conductor 2| is shown as leading from said swi element to the electrical device .to be controlled through'theswitchf i When the switch element is moved to the position shown in full lines in the drawing in Fig. 2, as by pulling uponthe cord 22 or in any other suitable manner, the switch will be in its circuit closing'position and permit current to flow to the electrical, device. as for example the lamp shown, the hook 01 the latch holding the switch in such position until released thereirom.

While in such position, the current will flow through the wire connected to the contact I! elongated sufllciently to actuate the latch from engagement with the switch, whereupon the spring l9 will retract the switch and open the circuit, or as shown, will turn oi! the light.

In order to turn oil the light prior to the normal period or time necessary to energize the thermostat su mcientlyto automatically accomplish this result, I have provided a cord 23 having one end connected to the thermostat or the 4 for example, from between five and ten minutes thereafter, this switch releasing element being operable by the heat from said current. Further.

spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, arrangement, construction, and combination or parts herein shown and described, or uses mentioned, except as limited by the claim.

What I claim as new and desire to secure by Letters Patent is: In an electrical switch for limiting the period or passing electrical current through a circuit and having a pair or electrical conductors for connection to said source or electrical current;

through said switch; a heating coil in, series in said circuit and connected to one of said con- .ductors and operably engageable with said switch member so as to conduct all of the current flowto releasably hold the same inclosed-circultposition and constantly actuated by said "last-mentioned means during the period that said circuit is closed, to release said switchf memlier after a predetermined amount oi. movement of said heatexpansible means caused by the iullnormal flow of current through said switch; and means independent of said heat-expansible means for manually releasing said latch from said switch member atany time prior to its release automatically by said expansible means.

recon man. 

